Healthier Homes – What can you do?
No more draughty, gas guzzling dwellings – my top tips for improving comfort, indoor health and energy efficiency.
The switch in most households to LED lighting was the largest contribution to the drop in the UK’s carbon emissions last year. Meanwhile, the incentives for renewable energy have been shamelessly cut while fossil fuel companies have retained their subsidies and fracking has been forced on communities against their will. So at the individual level in our homes or workspaces is there more scope for success where LEDs have led? Can we reduce demand to avoid any requirement for increased natural gas burning?
After many years in a design consultancy, I have recently attended some practical courses run by the Manchester Carbon Coop (“People powered retrofit” initiative). Out of this fusion of theory and practise, I have pulled together the following post which I hope will help you in your endeavours. Also, remember that there’s a YouTube video for just about anything so if you don’t know how to go about something, why not try an online tutorial (if my husband and I can do it, believe me, anyone can!).
I hope to have covered most bases, so here’s how you can do your bit.
1. Make a Plan
Energy efficiency measures tend to be the last thing on the list: far more urgent to fix the washing machine, choose wall paint and measure up for curtains (though the latter will improve your thermal comfort!)…
Make a plan and start to prioritise reducing your energy consumption FPS (For the Planet’s Sake)! This may mean making a few sacrifices in order to fund the improvements… and/or those savings that are earning next to nothing in terms of interest can start earning you actual savings on your energy bills… There are also government grants available based on income and benefits. Check out https://www.gov.uk/energy-grants-calculator to see if you qualify.
Make it fun and instructive – learn a new skill, and choose efficient light fittings and window frames on energy credentials with equal gusto!
2. Insulation
Adding insulation to your loft floor is likely to be the easiest measure – 270mm Rockwool or 300mm of sheep’s wool (the latter is lovely to the touch if you’re not allergic, and safe to install by yourself). In order to board over that thickness of insulation you will need to use pedestals so as not to squash the layers, as compressing the layer will significantly reduce how the material performs. Don’t forget the hatch!
To insulate the rafters instead takes a little more study, but you could fill the space between joists with the above materials, or more rigid insulation and then increase that thickness using spacers and boards underneath for an airtight sloping ceiling. Remember to use air tightness tape (see next point).
If you’re unsure as to how insulated your walls are, check by going through the building’s history, your EPC if you have one, and using a thermal imaging camera (you can borrow a camera from the Carbon Coop if you don’t have access to one – see my previous post!).
Insulate walls by filling cavities with bead insulation, wrapping the outside of the house with woodfibre insulation and render, or if you are in a conservation area and like your kerbside appearance, insulate on the inside (though this is more disruptive and therefore costly as it tends to mean moving radiators etc.). You will need to check the cavity walls as you go along with a thermal imaging camera to make sure all gaps have been filled, as otherwise you may end up with problems due to condensation forming in gaps.
Review your window situation. Single glazing should definitely be replaced, or consider secondary glazing at the very least. Is the double glazing over 20 years old? Have some of the seals gone (condensation or corrosion deposits in between panes)?
If you can afford to do so, install triple glazing: the internal temperatures will be significantly higher which will improve thermal comfort and together with good background ventilation, means that mould is unlikely to be able to grow. The frames are a big issue: they reduce the insulation value of your window overall, so the less frame you have for any particular window size, the better it performs. Also FSC wood is more sustainable (more insulating, rapidly renewable) than PVC so consider this when choosing frames. Thermally broken aluminium frames are also an option for those that prefer the metallic look, but generally less efficient.
Stretch target: find out if you can insulate the floors but be careful not to move the condensation point to anywhere in the floor joists, which could then rot. You may need an expert to assess this for you.
3. Air tightness
This is a biggie and the most difficult to get right.
For DIY tips on how to draught-proof your house, I would highly recommend the “pay as you feel” Carbon Coop courses, or look for a similar scheme near you. Essentially the thermal imaging survey will show you where your biggest problems are, especially on a windy day, though some of these will almost certainly be known to you already (have a good look, listen and feel of the back of your hand around frames and on internal surfaces). Most likely culprits: door surrounds and letterboxes, (sash) window frames, kitchen services to/from outside and loft hatches.
The issue with draughts is that they constitute “uncontrolled” ventilation, in other words they aren’t necessarily the rates of fresh air that you want/need, and not always in the right places/direction. Once you start closing up your building envelope though, you will need to mechanically ventilate, preferably with heat recovery as this will considerably reduce your heating requirements. Worried about fan power costs? Read this.
Stretch target: a Passivhaus retrofit (EnerPHit) requires the building to achieve nearly the same air tightness as a new build Passivhaus, which is generally successful only if junctions have been detailed correctly and workmanship on site is of a high quality. So how do you achieve this in an existing building? With great difficulty… It has been done before, and if I eventually manage it in my own house, I’ll have some more first-hand tips. I suspect it is likely to be more successful if you’re doing all the fabric improvements in one go!
4. Controls
If you don’t already have them, fit them, at the very least a central thermostat with time controls and TRVs on radiators. If you are able to, try to have some zone control. And to avoid moisture build up on walls / window frames, it is better to have unused rooms at a background level of heating rather than no heat at all as it keeps the relative humidity of the air in check .
If you do have some heating controls, then dig out that manual or google the make and model and start putting some sensible settings in – you don’t need the heating on 24/7, only when you’re likely to be in (you can always override as required). A bedroom should be cool at night so invest in a good duvet rather than have the boiler on.
For more fine control, there are Nest or Hive type controllers that will allow you to set temperatures and times remotely, and may even learn how you use your heating during the week and predict your settings for you.
With high temperature systems (most traditional radiator-based systems), an external temperature sensor for boiler modulation (called “weather compensated”) will also be of benefit.
5. Efficient appliances
Old appliances that have come to the end of their useful life should be replaced with as energy efficient models as possible (A+ to A+++).
We’ve already talked about LED lighting – just remember to replace old dimmer switches with LED compatible ones, because they won’t work otherwise. Not only that, but dimming LEDs will actually save energy, unlike incandescent or halogen bulbs, where dimming makes no difference to energy use.
6. Behaviours
Remember: a room doesn’t need light, you do. My parents drilled it into me from a young age, that if I left a room I should switch the light off. They are slightly more forgetful these days so I do it for them now… 😉
I also happen to be a terrible house guest and will turn off lights at other people’s if I think they’ve been left on “by mistake”… sorry!
By reducing the temperature at the thermostat by 1 degree, you could save £80 on your yearly heating bill alone, according to the Energy Saving Trust (a very good resource). An energy efficient heating system would be sized on a setpoint temperature of 20 °C, so see if you can reach that by putting a few extra layers of clothing, possibly going as far as 18 °C by reducing year on year.
Cut your water bill by installing a water meter, and by using water sparingly: 3min showers, turning off the tap while you’re brushing your teeth, using up veg rinsing/left over water for plants, not watering the lawn in dry spells (it will recover) etc.
Only a few things to remember then… Plan it in for a happy planet, and a happy pocket!
